McGill’s mission has also evolved over the past three years. He originally dubbed his overnights the Slave Cabin Project, but soon realized this conjured stereotypical wood shacks perched beside cotton fields. Now that he’s stayed in structures made of brick, stone and tabby, in cities and on small farms as well as plantations, he emphasizes the diversity of slave housing and of the slave experience. In talks and blog posts, he now speaks of his Slave Dwelling Project. He’s also cast his net far beyond his South Carolina base, at least to the degree that his budget allows. So far, McGill has stayed in 12 states, as far west as Texas and as far north as Connecticut. “We shouldn’t give the North a pass on slavery,” he says, since blacks were once enslaved there, too, and Northerners were key players in the slave trade, the purchase of slave-grown cotton, the sale of goods such as “Negro cloth” to slave owners, and other enterprises.

Northerners were also complicit politically, helping to craft a Constitution that safeguarded the rights of slaveholders and electing slaveholders in 12 of the nation’s first 16 presidential elections. Which leads McGill to ponder what is perhaps the biggest “big house” of them all. It was built with slave labor and serviced for decades by slaves who cooked and cleaned, among many other tasks. Slaves lived as well in the mansion, generally in the basement, though one “body servant” shared the bedroom of President Andrew Jackson.

“Staying at the White House, that would be the crown jewel,” McGill says dreamily, before dozing off at the cabin in Georgia. “I’ll have to get to work on making that happen.”